/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.zookeeper.server.upgrade;

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;

import org.apache.jute.Index;
import org.apache.jute.InputArchive;
import org.apache.jute.OutputArchive;
import org.apache.jute.Record;
import org.apache.zookeeper.data.ACL;
import org.apache.zookeeper.data.Stat;
import org.apache.zookeeper.data.StatPersistedV1;

/**
 * This class contains the data for a node in the data tree.
 * <p>
 * A data node contains a reference to its parent, a byte array as its data, an
 * array of ACLs, a stat object, and a set of its children's paths.
 * 
 */
public class DataNodeV1 implements Record {
	List<ACL> acl;

	HashSet<String> children = new HashSet<String>();

	byte data[];

	DataNodeV1 parent;

	public StatPersistedV1 stat;

	DataNodeV1() {
		// default rather than public constructor
	}

	DataNodeV1(DataNodeV1 parent, byte data[], List<ACL> acl, StatPersistedV1 stat) {
		this.parent = parent;
		this.data = data;
		this.acl = acl;
		this.stat = stat;
		this.children = new HashSet<String>();
	}

	public void copyStat(Stat to) {
		to.setAversion(stat.getAversion());
		to.setCtime(stat.getCtime());
		to.setCversion(stat.getCversion());
		to.setCzxid(stat.getCzxid());
		to.setMtime(stat.getMtime());
		to.setMzxid(stat.getMzxid());
		to.setVersion(stat.getVersion());
		to.setEphemeralOwner(stat.getEphemeralOwner());
		to.setDataLength(data.length);
		to.setNumChildren(children.size());
	}

	public void deserialize(InputArchive archive, String tag) throws IOException {
		archive.startRecord("node");
		data = archive.readBuffer("data");
		Index i = archive.startVector("acl");
		if (i != null) {
			acl = new ArrayList<ACL>();
			while (!i.done()) {
				ACL a = new ACL();
				a.deserialize(archive, "aclEntry");
				acl.add(a);
				i.incr();
			}
		}
		archive.endVector("acl");
		stat = new StatPersistedV1();
		stat.deserialize(archive, "stat");
		archive.endRecord("node");
	}

	/**
	 * convenience methods to get the children
	 * 
	 * @return the children of this datanode
	 */
	public HashSet<String> getChildren() {
		return this.children;
	}

	synchronized public void serialize(OutputArchive archive, String tag) throws IOException {
		archive.startRecord(this, "node");
		archive.writeBuffer(data, "data");
		archive.startVector(acl, "acl");
		if (acl != null) {
			for (ACL a : acl) {
				a.serialize(archive, "aclEntry");
			}
		}
		archive.endVector(acl, "acl");
		stat.serialize(archive, "stat");
		archive.endRecord(this, "node");
	}

	/**
	 * convenience method for creating DataNode fully
	 * 
	 * @param children
	 */
	public void setChildren(HashSet<String> children) {
		this.children = children;
	}
}
